<h3>New experimental advanced parameters API</h3><pre></pre><b><pre></pre></b><BR>
<pre><b>typedef enum {
</b>/* compression parameters */<b>
- ZSTD_p_compressionLevel=100, </b>/* Update all compression parameters according to pre-defined cLevel table (default:3) */<b>
+ ZSTD_p_compressionLevel=100, </b>/* Update all compression parameters according to pre-defined cLevel table<b>
+ * Default level is 3.
+ * Special: value 0 means "do not change cLevel". */
ZSTD_p_windowLog, </b>/* Maximum allowed back-reference distance, expressed as power of 2.<b>
* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
* default value : set through compressionLevel */
* More attempts result in better and slower compression.
* This parameter is useless when using "fast" and "dFast" strategies */
ZSTD_p_minMatchLength, </b>/* Minimum match size (except for repeat-matches, which limit is hard-coded).<b>
- * Larger values make compression and decompression faster, but decrease compression ratio
+ * Larger values make faster compression and decompression, but decrease ratio.
* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
* Note that currently, for all strategies < btopt, effective minimum is 4.
* Note that currently, for all strategies > fast, effective maximum is 6. */
* Length of Match considered "good enough" to stop search.
* Larger values make compression stronger and slower. */
ZSTD_p_compressionStrategy, </b>/* See ZSTD_strategy enum definition.<b>
- * Cast selected strategy into unsigned for ZSTD_CCtx_setParameter() compatibility.
+ * Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
* The higher the value of selected strategy, the more complex it is,
* resulting in stronger and slower compression */
#if 0
</p></pre><BR>
-<pre><b>size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx);
+<pre><b>// Not ready yet !!!
+size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx);
</b><p> Return a CCtx to clean state.
Useful after an error, or to interrupt an ongoing compression job and start a new one.
It's allowed to change compression parameters after a reset.
*/
+/*-*************************************
+* Tuning parameters
+***************************************/
+#ifndef ZSTD_DEFAULT_CLEVEL
+# define ZSTD_DEFAULT_CLEVEL 3
+#endif
+
/*-*************************************
* Dependencies
***************************************/
U32 rep[ZSTD_REP_NUM];
U32 repToConfirm[ZSTD_REP_NUM];
U32 dictID;
+ int compressionLevel;
ZSTD_parameters params;
void* workSpace;
size_t workSpaceSize;
if (!cctx) return NULL;
memset(cctx, 0, sizeof(ZSTD_CCtx));
cctx->customMem = customMem;
+ cctx->compressionLevel = ZSTD_DEFAULT_CLEVEL;
return cctx;
}
+ cctx->outBuffSize + cctx->inBuffSize;
}
+/* private API call, for dictBuilder only */
+const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) { return &(ctx->seqStore); }
+
+static ZSTD_parameters ZSTD_getParamsFromCCtx(const ZSTD_CCtx* cctx) { return cctx->params; }
+
/* older variant; will be deprecated */
size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter param, unsigned value)
{
}
}
-const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) /* hidden interface */
+size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value)
+{
+# define CLAMPCHECK(val,min,max) { if ((val<min) | (val>max)) return ERROR(compressionParameter_unsupported); }
+# define LOADCPARAMS(cParams) \
+ if (cctx->compressionLevel!=0) { \
+ cParams = ZSTD_getCParams( \
+ cctx->compressionLevel, \
+ cctx->frameContentSize, 0); /* dictSize unknown at this stage */ \
+ cctx->compressionLevel = 0; \
+ }
+
+
+ switch(param)
+ {
+ case ZSTD_p_compressionLevel :
+ if ((int)value > ZSTD_maxCLevel()) value = ZSTD_maxCLevel(); /* cap max compression level */
+ if (value == 0) return 0; /* special value : 0 means "don't change anything" */
+ cctx->compressionLevel = value;
+ return 0;
+
+ case ZSTD_p_windowLog :
+ CLAMPCHECK(value, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.windowLog = value;
+ return 0;
+
+ case ZSTD_p_hashLog :
+ CLAMPCHECK(value, ZSTD_HASHLOG_MIN, ZSTD_HASHLOG_MAX);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.hashLog = value;
+ return 0;
+
+ case ZSTD_p_chainLog :
+ CLAMPCHECK(value, ZSTD_CHAINLOG_MIN, ZSTD_CHAINLOG_MAX);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.chainLog = value;
+ return 0;
+
+ case ZSTD_p_searchLog :
+ CLAMPCHECK(value, ZSTD_SEARCHLOG_MIN, ZSTD_SEARCHLOG_MAX);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.searchLog = value;
+ return 0;
+
+ case ZSTD_p_minMatchLength :
+ CLAMPCHECK(value, ZSTD_SEARCHLENGTH_MIN, ZSTD_SEARCHLENGTH_MAX);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.searchLength = value;
+ return 0;
+
+ case ZSTD_p_targetLength :
+ CLAMPCHECK(value, ZSTD_TARGETLENGTH_MIN, ZSTD_TARGETLENGTH_MAX);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.targetLength = value;
+ return 0;
+
+ case ZSTD_p_compressionStrategy :
+ if (value > (unsigned)ZSTD_btultra) return ERROR(compressionParameter_unsupported);
+ LOADCPARAMS(cctx->params.cParams);
+ cctx->params.cParams.strategy = (ZSTD_strategy)value;
+ return 0;
+
+#if 0
+ case ZSTD_p_windowSize : /* to be done later */
+ return ERROR(compressionParameter_unsupported);
+#endif
+
+ case ZSTD_p_contentSizeFlag : /* Content size will be written in frame header _when known_ (default:1) */
+ cctx->params.fParams.contentSizeFlag = value>0;
+ return 0;
+
+ case ZSTD_p_contentChecksumFlag : /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */
+ cctx->params.fParams.checksumFlag = value>0;
+ return 0;
+
+ case ZSTD_p_dictIDFlag : /* When applicable, the dictID of used dictionary will be provided in frame header (default:1) */
+ cctx->params.fParams.noDictIDFlag = value==0;
+ return 0;
+
+ case ZSTD_p_refDictContent : /* to be done later */
+ return ERROR(compressionParameter_unsupported);
+
+ case ZSTD_p_forceMaxWindow : /* Force back-references to remain < windowSize,
+ * even when referencing into Dictionary content
+ * default : 0 when using a CDict, 1 when using a Prefix */
+ cctx->forceWindow = value>0;
+ cctx->loadedDictEnd = 0;
+ return 0;
+
+ case ZSTD_p_rawContentDict : /* load dictionary in "content-only" mode (no header analysis) (default:0) */
+ cctx->forceRawDict = value>0;
+ return 0;
+
+ default: return ERROR(parameter_unknown);
+ }
+}
+
+ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize)
+{
+ cctx->frameContentSize = pledgedSrcSize;
+ return 0;
+}
+
+/* Not ready yet ! */
+ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
{
- return &(ctx->seqStore);
+ (void)cctx; (void)prefix; (void)prefixSize; /* to be done later */
+ return ERROR(compressionParameter_unsupported);
}
-static ZSTD_parameters ZSTD_getParamsFromCCtx(const ZSTD_CCtx* cctx)
+/* Not ready yet ! */
+ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
{
- return cctx->params;
+ (void)cctx; (void)cdict; /* to be done later */
+ return ERROR(compressionParameter_unsupported);
}
/*-===== Pre-defined compression levels =====-*/
-#define ZSTD_DEFAULT_CLEVEL 1
#define ZSTD_MAX_CLEVEL 22
int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
size_t const addedSize = srcSize ? 0 : 500;
U64 const rSize = srcSize+dictSize ? srcSize+dictSize+addedSize : (U64)-1;
U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB); /* intentional underflow for srcSizeHint == 0 */
- if (compressionLevel <= 0) compressionLevel = ZSTD_DEFAULT_CLEVEL; /* 0 == default; no negative compressionLevel yet */
+ if (compressionLevel <= 0) compressionLevel = 1; /* 0 == default; no negative compressionLevel yet */
if (compressionLevel > ZSTD_MAX_CLEVEL) compressionLevel = ZSTD_MAX_CLEVEL;
cp = ZSTD_defaultCParameters[tableID][compressionLevel];
if (MEM_32bits()) { /* auto-correction, for 32-bits mode */
typedef enum {
/* compression parameters */
- ZSTD_p_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table (default:3) */
+ ZSTD_p_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
+ * Default level is 3.
+ * Special: value 0 means "do not change cLevel". */
ZSTD_p_windowLog, /* Maximum allowed back-reference distance, expressed as power of 2.
* Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
* default value : set through compressionLevel */
* More attempts result in better and slower compression.
* This parameter is useless when using "fast" and "dFast" strategies */
ZSTD_p_minMatchLength, /* Minimum match size (except for repeat-matches, which limit is hard-coded).
- * Larger values make compression and decompression faster, but decrease compression ratio
+ * Larger values make faster compression and decompression, but decrease ratio.
* Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
* Note that currently, for all strategies < btopt, effective minimum is 4.
* Note that currently, for all strategies > fast, effective maximum is 6. */
* Length of Match considered "good enough" to stop search.
* Larger values make compression stronger and slower. */
ZSTD_p_compressionStrategy, /* See ZSTD_strategy enum definition.
- * Cast selected strategy into unsigned for ZSTD_CCtx_setParameter() compatibility.
+ * Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
* The higher the value of selected strategy, the more complex it is,
* resulting in stronger and slower compression */
#if 0
projects / thirdparty / zstd.git / commitdiff
